Major Degregation / Packet Loss / Speeds

Subscriber to Cox in the 23322 Chesapeake, VA area

Family has been experiencing extremely unreliable internet over the past month while I was out at sea for the Navy.

I checked my speeds on my PC directly connected to my Router. At best I'm getting 250mb. I pay for 1gig

I've rebooted the router (UDMP) and modem (SB8200) on multiple occasions without much difference.

I would please like some assistance. 

Thank you.

Attached is a screensh

ot of my ISP connection status. I've never had this much degraded internet since moving here. There have been days where it's much more degraded.